Most of the currently available mobile devices, such as notebook computers, tablet computers and smartphones, have a slim body and a largely increased computing speed. The electronic elements in the mobile devices for executing the computation at high speed also produce a large amount of heat during operation thereof. For the purpose of being conveniently portable, the mobile devices have a largely reduced overall thickness. And, to prevent invasion by foreign matters and moisture, the mobile devices are provided with only an earphone port and some necessary connection ports but not other open holes that allow air convection between the narrow internal space of the mobile devices and the external environment. Therefore, due to the small thickness of the mobile devices, the large amount of heat produced by the electronic elements in the mobile devices, such as the computation executing units and the battery, can not be quickly dissipated into the external environment. Further, due to the closed narrow internal space of the mobile devices, it is difficult for the heat produced by the electronic elements to dissipate through air convection. As a result, heat tends to accumulate or gather in the mobile devices to adversely affect the working efficiency or even cause crash of the mobile devices.
To solve the above problems, some passive type heat dissipation elements, such as heat spreader, vapor chamber, heat sink, etc., are mounted in the mobile devices to assist in heat dissipation thereof. Due to the small thickness and the narrow internal space of the mobile devices, these passive type heat dissipation elements must also be extremely thin to be mounted in the very limited internal space of the mobile devices. However, the wick structure and the vapor passage in the size reduced heat spreader and vapor chamber are also reduced in size to result in largely lowered heat transfer efficiency of the heat spreader and the vapor chamber and accordingly, poor heat dissipation performance thereof. In brief, when the internal computing units of the mobile devices have an extremely high power, the conventional heat spreader and vapor chambers just could not effectively dissipate the heat produced by the high power computing units.